Spark plug



March 8 1927' G. w. GARDNER srARK PLUG Filed Feb.1. 1926 Patented Mar.8, 1927. i

UNITED STATES GEORGE W. GARDNER, Oli" FLINT, MICHIGAN.

SPARK PLUG.

Application filed February This invention has relation to spark plugsfor internal combustion engines, and more particularly to the formationand construction of the points or electrodes thereof.

The main object of the invention, is the provision of a spark plug whichshall bc quite simple and inexpensive to manufacture, or repair, shouldany of its parts become broken or injured, of assemblage andapplication, as well as, of such construction, arrangement and formationof certain of its parts, as to afford a more highly efficient device ofthis character or class, than has heretofore been in common or generaluse, especially, with regard to the characteristics of the sparksproduced and the cleanliness of the points or electrodes, or theprevention or elimination of carbon thereon or therefrom.

More specifically speaking, the invention contemplates as another of itsobjects, a spark plug in which the primary and secondary electrodes orpoints thereof, each has its adjacent end to the other electrode split,or provided with a reversed substantially V-shaped recess in registerwith one another, thereby forming a substantially diamond shaped openingbetween the adjacent ends of the electrodes for increasing theirsparking capacity and causing the electric current to spread and jumpall through the split portions of the electrodes.

The invention also has as one of its features, the provision of theadjacent walls of said recesses each with an edge formed substantially,knife edged in shape, whereby the current will be caused to be condensedin its act of jumping or passing from the side walls of one of therecesses to the other side walls of the same recess, and from thencethrough the adjacent faces of the split electrodes, which faces arespaced the required distance apart and provide the `requisite sparkinggap between them. Also, this forf mation of the walls of each recessserves to .make them self-cleaning, or reduces to a minimum theaccumulation of carbon or oil at the tips or adjacent faces of theelectrodes, thereby causing them to effect a stronger, more positive orcertain sparking action.

Other objects and advantages of the invention will become apparent fromthe following description and explanation.

The invention consists in certain peculiarities, of the construction,novel combina- 1, 1926. Serial No. 85,177.

tion and arrangement of the various parts thereof, as will behereinafter more fully set forth and specifically claimed.

in the accompanying drawing, which serves to `illustrate an embodimentof the invcntion:

Figure l. is a view in elevation of a spark plug embodying my inventionshowing the parts thereof in about the positions they will occupy whenthe device is ready for use.

Figure 2 is a view partly in section and partly in elevation, showingthe` sides of the electrodes, and

Figure 3 is a similar view, but showing face views of parts of theelectrodes.

Similar numerals of reference designate like parts throughout thedifferent views of l 1 the drawing. Y

The spark plug is shown in the present instance, of the separable typefor the convenience of repairing the same, but it will be understoodthat the illustration is for the purpose of eXemplifioation only, andthat other types, or the standard makes, maybe employed; without adeparture from the spirit of my invention, so long as they employelectrodes of the construction covered by the appended claim.

By reference to the drawing, it will be understood that the spark plugis made up of a centrally hollow plug 4, which has its lower portionscrew threaded as at 5, to engage an opening in the cylinder of aninternal combustion engine, and its upper portion formed with an angularhead 6, which can be engaged by a wrench used for attaching said plug inplace, and a porcelain, or an insulator core 7, having a central boreeX- tended longitudinally therethrough. The member 7, is fitted in thehollow ofpthe plug 4, and held in place by means of a surrounding nut 8,engaging the screw threaded portion of the upper part of said plug.

Extended through the bore of the core 7, is the primary electrode 9, thelower end of which projects slightly beyond the lower ex'- tremity ofthe member 4, as shown, and has said end split as will be presentlyexplained. The upper end of the electrode 9, extends through the upperend of the core 7, and has thereon a nut 10, used for fastening it toone of the current wires of an ignition system (not shown).

Fixed in a suitable opening in the lower edge of the member 4, is theupper end of the secondary electrode 1l, the opposite portion ot' whichis curved inwardly and upwardly so that its said vertical part alignswith the lower portion of the primary electrode. As shown, the adjacentextremity ot each otthe electrodes is split, or pi'o\\'ided each with apair ot diverging prongs 12, and 13, which are spaced apart, but i. iththeir tip ends i registry with one another to provide the requisitesparking gap. The tips or faces of the ends ot the prongs are preferablyilat and the inner surface of each ot the prongs l2, and 18, are usuallyot a knife-edge structure, as shown.

t is apparent that by employing a spark plug,` embodying,v inyinuiroveinents, the points of tl s, electrodes can be tornied by the useot suitable dies, are preferably niade ot basic wire ot suitable sii/ie,and that the sparking),l e'liiciency oi the plug;` will be increased,inore reliable and the sparks stronger or more intense in heat.

It is further obvious, that by reason of the divergjen-iiry ot theprongs 12, and 13, or rather, by reason et the divergency of the innersurfaces oit each pair ot said prongs, and by reason ot the 'fact thatthe end oij each electrode is split, the inner surfaces vwill beshielded by the outer portions of each split or recess, as well as thetips and thus prevent the accumulation ot' foreign matter thereon. f

llaving thus tuliy described the. invention, what it claini as new anddesire to Secure by Letters Patent is;

in a spark plug, the combination with a plug` having;` means to secureit to a cylinder ot an engine, ot priniary and secondary electrodesmounted thereon and l'iafingv one ot' their ends in juxtaposition andsubstair tial. ali gnnient with each other, each ot said adjacent endsot said electrodes having a )air ot' divereent )roues havin@ their or CC D tions adjacent their tips reduced.

GEURGE lV. GARDNER.

